Low voltage disconnect
A load voltage disconnect (LVD) is a key component of a PV system that disconnects loads from the battery bank if the battery bank drops below a certain voltage. This is important as it protects the batteries from over-discharge which can greatly reduce their cycle life. A low voltage disconnect is often integrated into charge controllers and inverters, but also may be a stand-alone component when larger DC loads, like water pumps or refrigerators, that need to be connected directly to the battery bank are used. If the LVD is integrated into a charge controller or inverter, it is important to check whether it is possible to program a higher or lower voltage that may better suit the needs of the system. The LVD voltage on these devices is often set very low at around 10-20% state of charge. It is important to note that voltage of a battery bank can drop rapidly if it is put under significant load and could cause a LVD with too high of a value to disconnect the loads when it is not desirable.